I finally got the Digging Ray skill, but instead of destroying walls, it destroyed only visually and replaced them with invisible walls
How did you shoot it? I've had no problems using it, but if you shoot a diagonal line, you may have to weave in and out to get it to work. Never tried shooting it out of the map, but that may also be the issue. Also, make sure when you shoot it you have your mouse far away or else it won't destroy as much of the wall. Happen to have a screenshot?
I shot many times, making a big hole, but it still didn't work *edit* Ok, now when i reloaded the game to take a screenshot, the invisible wall is gone So, if anybody else has this problem - you need to reload the game! Here's the screenshot, if anyone needs it. The invisible wall was the corner that i shot off from the wall that's toward northwest from the character:
It takes some practice but aim for the end of where you want cleared, seems to work slightly better but it is annoying with that high mana cost...